When a microphone is being used outdoors in a windy environment the wind can cause air turbulence in the vicinity of the microphone. The turbulence is produced by pulsing of the air flow as it meets obstacles such as a housing of the microphone. For example, such a housing may comprise a casing of a radio communication unit incorporating the microphone. The turbulence is a source of localised changes in air pressure and air flow speed. The turbulence is a source of noise in the microphone which has a frequency spectrum in the audio frequency range. The noise degrades a speech signal being picked up at the microphone. When the wind is very strong the noise it produces may be of such a high level that the speech signal becomes unintelligible.
A known method of reducing wind produced noise experienced by a microphone involves providing a protective covering over the microphone using an open cell foam material. The problem with employing this method is that a relatively large amount of the foam material is normally required to give a suitable reduction of wind noise. Unfortunately, the known method is not suitable for use in protecting a microphone incorporated in a hand portable radio communication unit such as a portable radio, mobile telephone or the like. In such units components such as the microphone have to be suitably small and compact and use of a large amount of protective material is not appropriate.